Press Reviews

Argentina’s Pampa Amarilla is a rather remote place, a dry plain stretching thousands of miles against the spectacular backdrop of the rugged, snowcapped peaks of the Andes. Like every other place on Earth, the yellow pampa is bathed in a constant shower of cosmic rays—protons and atomic nuclei that fly through the universe at close to the speed of light. While some are known to come from the sun, most take a meandering path that gives no clue to where they came from. Once in a while, an unusually powerful cosmic ray strikes the Earth’s atmosphere with almost as much energy as a bullet. Fortunately, such a projectile is no danger to human life. Entering the atmosphere, it loses energy and creates showers of lower-energy particles, which can spread across more than 15 square miles by the time they hit ground.

The Pierre Auger Collaboration has begun the public release of one percent of the cosmic-ray events recorded by the Observatory in Argentina. New cosmic-ray data—about 70 events per day—will be posted on a daily basis.

The one-percent release is part of the worldwide Pierre Auger education and outreach program. It will allow teachers to expose students to real scientific data and the breathtaking processes that take place in the cosmos, hurling charged particles toward Earth. Data are provided both as graphical displays and in tabular form. For each cosmic-ray air shower, the Web sites show the energy and direction of the incoming cosmic-ray particle. The public data provides information on cosmic-rays with extremely high energy, up to 5 x 1019 electron volts (eV).